What am I doing wrong ? Sleeping patterns

My son is 6 weeks and last night he slept up to 4 hours one time sleeping in his bassinet swaddled perfectly, no use of a binky, would fall asleep on his own but tonight he’s sleeping in his swing and he needs his binky and will not fall asleep. I’m so confused he did an amazing job last night every single time I would put him down to sleep and tonight’s a totally different baby. Is there something I could be doing wrong during the day? I she not sleeping enough is it the swing ? Is he not getting the right amount or type of breast milk ? Is he over tired? I don’t know any ideas ladies???? I’m lost